Java Code Examples for org.apache.bcel.generic.MethodGen#getInstructionList()

private void analyzeMethod(Method m, ClassContext classContext) throws CFGBuilderException, DataflowAnalysisException {
    MethodGen methodGen = classContext.getMethodGen(m);
    ConstantPoolGen cpg = classContext.getConstantPoolGen();
    CFG cfg = classContext.getCFG(m);

    if (methodGen == null || methodGen.getInstructionList() == null) {
        return; //No instruction .. nothing to do
    }
    for (Iterator<Location> i = cfg.locationIterator(); i.hasNext(); ) {
        Location location = i.next();
        Instruction inst = location.getHandle().getInstruction();
        if (inst instanceof InvokeInstruction) {
            InvokeInstruction invoke = (InvokeInstruction) inst;
            String methodName = invoke.getMethodName(cpg);
            if ("enableDefaultTyping".equals(methodName)) {
                JavaClass clz = classContext.getJavaClass();
                bugReporter.reportBug(new BugInstance(this, DESERIALIZATION_TYPE, HIGH_PRIORITY)
                        .addClass(clz)
                        .addMethod(clz, m)
                        .addCalledMethod(cpg, invoke)
                        .addSourceLine(classContext, m, location)
                );
            }
        }
    }
}
 

/**
 * BCEL-262:
 */
public void testB262() throws ClassNotFoundException
{
    final JavaClass clazz = getTestClass(PACKAGE_BASE_NAME+".data.PLSETestEnum");
    final ClassGen gen = new ClassGen(clazz);
    final ConstantPoolGen pool = gen.getConstantPool();
    // get the values() method
    final Method m = gen.getMethodAt(0);
    final MethodGen mg = new MethodGen(m, gen.getClassName(), pool);
    final InstructionList il = mg.getInstructionList();
    // get the invokevirtual instruction
    final InstructionHandle ih = il.findHandle(3);
    final InvokeInstruction ii = (InvokeInstruction)(ih.getInstruction());
    // without fix, the getClassName() will throw:
    //   java.lang.IllegalArgumentException: Cannot be used on an array type
    final String cn = ii.getClassName(pool);
    assertEquals("[Lorg.apache.bcel.data.PLSETestEnum;", cn);
}
 

private void analyzeMethod(Method m, ClassContext classContext) throws CFGBuilderException, DataflowAnalysisException
    {

        MethodGen methodGen = classContext.getMethodGen(m);
        ConstantPoolGen cpg = classContext.getConstantPoolGen();
        CFG cfg = classContext.getCFG(m);

        if (methodGen == null || methodGen.getInstructionList() == null) {
            return; //No instruction .. nothing to do
        }

        for (Iterator<Location> i = cfg.locationIterator(); i.hasNext(); ) {
            Location location = i.next();
            Instruction inst = location.getHandle().getInstruction();

            //
            if (inst instanceof InvokeInstruction) {
//                System.out.println(inst.getName());
                InvokeInstruction invoke = (InvokeInstruction) inst;

                String className = invoke.getClassName(cpg);
                if ("java.io.ObjectInputStream".equals(className) || className.contains("InputStream") || InterfaceUtils.isSubtype(className, "java.io.ObjectInputStream")) {

                    String methodName = invoke.getMethodName(cpg);
                    if (OBJECT_INPUTSTREAM_READ_METHODS.contains(methodName)) {

                        JavaClass clz = classContext.getJavaClass();
                        bugReporter.reportBug(new BugInstance(this, OBJECT_DESERIALIZATION_TYPE, HIGH_PRIORITY) //
                                .addClass(clz).addMethod(clz, m).addSourceLine(classContext,m,location));
                    }
                }

            }
        }
    }
 

byte[] nullAdaptClass(final InputStream is, final String name)
        throws Exception
{
    JavaClass jc = new ClassParser(is, name + ".class").parse();
    ClassGen cg = new ClassGen(jc);
    ConstantPoolGen cp = cg.getConstantPool();
    Method[] ms = cg.getMethods();
    for (int j = 0; j < ms.length; ++j) {
        MethodGen mg = new MethodGen(ms[j], cg.getClassName(), cp);
        boolean lv = ms[j].getLocalVariableTable() == null;
        boolean ln = ms[j].getLineNumberTable() == null;
        if (lv) {
            mg.removeLocalVariables();
        }
        if (ln) {
            mg.removeLineNumbers();
        }
        mg.stripAttributes(skipDebug);
        InstructionList il = mg.getInstructionList();
        if (il != null) {
            InstructionHandle ih = il.getStart();
            while (ih != null) {
                ih = ih.getNext();
            }
            if (compute) {
                mg.setMaxStack();
                mg.setMaxLocals();
            }
        }
        cg.replaceMethod(ms[j], mg.getMethod());
    }
    return cg.getJavaClass().getBytes();
}
 

byte[] nullAdaptClass(final InputStream is, final String name)
        throws Exception
{
    JavaClass jc = new ClassParser(is, name + ".class").parse();
    ClassGen cg = new ClassGen(jc);
    ConstantPoolGen cp = cg.getConstantPool();
    Method[] ms = cg.getMethods();
    for (int j = 0; j < ms.length; ++j) {
        MethodGen mg = new MethodGen(ms[j], cg.getClassName(), cp);
        boolean lv = ms[j].getLocalVariableTable() == null;
        boolean ln = ms[j].getLineNumberTable() == null;
        if (lv) {
            mg.removeLocalVariables();
        }
        if (ln) {
            mg.removeLineNumbers();
        }
        mg.stripAttributes(skipDebug);
        InstructionList il = mg.getInstructionList();
        if (il != null) {
            InstructionHandle ih = il.getStart();
            while (ih != null) {
                ih = ih.getNext();
            }
            if (compute) {
                mg.setMaxStack();
                mg.setMaxLocals();
            }
        }
        cg.replaceMethod(ms[j], mg.getMethod());
    }
    return cg.getJavaClass().getBytes();
}
 

public Method injection(final JavaClass clazz, Method method, final ConstantPoolGen cp, final int firstStringOffset) {
    final MethodGen methodGen = new MethodGen(method, clazz.getClassName(), cp);

    final InstructionList instructionList = methodGen.getInstructionList();
    instructionList.insert(instructionList.getStart(), makeWillBeAddedInstructionList(methodGen, firstStringOffset));

    methodGen.setMaxStack();
    methodGen.setMaxLocals();

    method = methodGen.getMethod();
    instructionList.dispose();

    return method;
}
 

@Benchmark
public void generator(Blackhole bh) throws IOException {
    JarFile jar = getJarFile();

    for (JarEntry entry : getClasses(jar)) {
        byte[] bytes = IOUtils.toByteArray(jar.getInputStream(entry));

        JavaClass clazz = new ClassParser(new ByteArrayInputStream(bytes), entry.getName()).parse();

        ClassGen cg = new ClassGen(clazz);

        for (Method m : cg.getMethods()) {
            MethodGen mg = new MethodGen(m, cg.getClassName(), cg.getConstantPool());
            InstructionList il = mg.getInstructionList();

            if (il != null) {
                mg.getInstructionList().setPositions();
                mg.setMaxLocals();
                mg.setMaxStack();
            }
            cg.replaceMethod(m, mg.getMethod());
        }

        bh.consume(cg.getJavaClass().getBytes());
    }

    jar.close();
}
 

/**
 * Determine whether or not the the given method is a getter method. I.e.,
 * if it just returns the value of an instance field.
 *
 * @param classContext
 *            the ClassContext for the class containing the method
 * @param method
 *            the method
 */
public static boolean isGetterMethod(ClassContext classContext, Method method) {
    MethodGen methodGen = classContext.getMethodGen(method);
    if (methodGen == null) {
        return false;
    }
    InstructionList il = methodGen.getInstructionList();
    // System.out.println("Checking getter method: " + method.getName());
    if (il.getLength() > 60) {
        return false;
    }

    int count = 0;
    for (InstructionHandle ih : il) {
        switch (ih.getInstruction().getOpcode()) {
        case Const.GETFIELD:
            count++;
            if (count > 1) {
                return false;
            }
            break;
        case Const.PUTFIELD:
        case Const.BALOAD:
        case Const.CALOAD:
        case Const.DALOAD:
        case Const.FALOAD:
        case Const.IALOAD:
        case Const.LALOAD:
        case Const.SALOAD:
        case Const.AALOAD:
        case Const.BASTORE:
        case Const.CASTORE:
        case Const.DASTORE:
        case Const.FASTORE:
        case Const.IASTORE:
        case Const.LASTORE:
        case Const.SASTORE:
        case Const.AASTORE:
        case Const.PUTSTATIC:
            return false;
        case Const.INVOKESTATIC:
        case Const.INVOKEVIRTUAL:
        case Const.INVOKEINTERFACE:
        case Const.INVOKESPECIAL:
        case Const.GETSTATIC:
            // no-op

        }
    }
    // System.out.println("Found getter method: " + method.getName());
    return true;
}
 

byte[] counterAdaptClass(final InputStream is, final String name)
        throws Exception
{
    JavaClass jc = new ClassParser(is, name + ".class").parse();
    ClassGen cg = new ClassGen(jc);
    ConstantPoolGen cp = cg.getConstantPool();
    if (!cg.isInterface()) {
        FieldGen fg = new FieldGen(ACC_PUBLIC,
                Type.getType("I"),
                "_counter",
                cp);
        cg.addField(fg.getField());
    }
    Method[] ms = cg.getMethods();
    for (int j = 0; j < ms.length; ++j) {
        MethodGen mg = new MethodGen(ms[j], cg.getClassName(), cp);
        if (!mg.getName().equals("<init>") && !mg.isStatic()
                && !mg.isAbstract() && !mg.isNative())
        {
            if (mg.getInstructionList() != null) {
                InstructionList il = new InstructionList();
                il.append(new ALOAD(0));
                il.append(new ALOAD(0));
                il.append(new GETFIELD(cp.addFieldref(name, "_counter", "I")));
                il.append(new ICONST(1));
                il.append(new IADD());
                il.append(new PUTFIELD(cp.addFieldref(name, "_counter", "I")));
                mg.getInstructionList().insert(il);
                mg.setMaxStack(Math.max(mg.getMaxStack(), 2));
                boolean lv = ms[j].getLocalVariableTable() == null;
                boolean ln = ms[j].getLineNumberTable() == null;
                if (lv) {
                    mg.removeLocalVariables();
                }
                if (ln) {
                    mg.removeLineNumbers();
                }
                cg.replaceMethod(ms[j], mg.getMethod());
            }
        }
    }
    return cg.getJavaClass().getBytes();
}
 

byte[] counterAdaptClass(final InputStream is, final String name)
        throws Exception
{
    JavaClass jc = new ClassParser(is, name + ".class").parse();
    ClassGen cg = new ClassGen(jc);
    ConstantPoolGen cp = cg.getConstantPool();
    if (!cg.isInterface()) {
        FieldGen fg = new FieldGen(ACC_PUBLIC,
                Type.getType("I"),
                "_counter",
                cp);
        cg.addField(fg.getField());
    }
    Method[] ms = cg.getMethods();
    for (int j = 0; j < ms.length; ++j) {
        MethodGen mg = new MethodGen(ms[j], cg.getClassName(), cp);
        if (!mg.getName().equals("<init>") && !mg.isStatic()
                && !mg.isAbstract() && !mg.isNative())
        {
            if (mg.getInstructionList() != null) {
                InstructionList il = new InstructionList();
                il.append(new ALOAD(0));
                il.append(new ALOAD(0));
                il.append(new GETFIELD(cp.addFieldref(name, "_counter", "I")));
                il.append(new ICONST(1));
                il.append(new IADD());
                il.append(new PUTFIELD(cp.addFieldref(name, "_counter", "I")));
                mg.getInstructionList().insert(il);
                mg.setMaxStack(Math.max(mg.getMaxStack(), 2));
                boolean lv = ms[j].getLocalVariableTable() == null;
                boolean ln = ms[j].getLineNumberTable() == null;
                if (lv) {
                    mg.removeLocalVariables();
                }
                if (ln) {
                    mg.removeLineNumbers();
                }
                cg.replaceMethod(ms[j], mg.getMethod());
            }
        }
    }
    return cg.getJavaClass().getBytes();
}
 

/**
 * Patch a method.
 */
private static Method helloifyMethod(Method m) {
    final Code code = m.getCode();
    final int flags = m.getAccessFlags();
    final String name = m.getName();

    // Sanity check
    if (m.isNative() || m.isAbstract() || (code == null)) {
        return m;
    }

    // Create instruction list to be inserted at method start.
    final String mesg = "Hello from " + Utility.methodSignatureToString(m.getSignature(),
            name,
            Utility.accessToString(flags));
    final InstructionList patch = new InstructionList();
    patch.append(new GETSTATIC(out));
    patch.append(new PUSH(cp, mesg));
    patch.append(new INVOKEVIRTUAL(println));

    final MethodGen mg = new MethodGen(m, class_name, cp);
    final InstructionList il = mg.getInstructionList();
    final InstructionHandle[] ihs = il.getInstructionHandles();

    if (name.equals("<init>")) { // First let the super or other constructor be called
        for (int j = 1; j < ihs.length; j++) {
            if (ihs[j].getInstruction() instanceof INVOKESPECIAL) {
                il.append(ihs[j], patch); // Should check: method name == "<init>"
                break;
            }
        }
    } else {
        il.insert(ihs[0], patch);
    }

    // Stack size must be at least 2, since the println method takes 2 argument.
    if (code.getMaxStack() < 2) {
        mg.setMaxStack(2);
    }

    m = mg.getMethod();

    il.dispose(); // Reuse instruction handles

    return m;
}
 

private static Method removeNOPs(final MethodGen mg) {
    final InstructionList il = mg.getInstructionList();
    final InstructionFinder f = new InstructionFinder(il);
    final String pat = "NOP+"; // Find at least one NOP
    InstructionHandle next = null;
    int count = 0;

    for (final Iterator<InstructionHandle[]> e = f.search(pat); e.hasNext(); ) {
        final InstructionHandle[] match = e.next();
        final InstructionHandle first = match[0];
        final InstructionHandle last = match[match.length - 1];

        // Some nasty Java compilers may add NOP at end of method.
        if ((next = last.getNext()) == null) {
            break;
        }

        count += match.length;

        // Delete NOPs and redirect any references to them to the following (non-nop) instruction.
        try {
            il.delete(first, last);
        } catch (final TargetLostException e2) {
            for (final InstructionHandle target : e2.getTargets()) {
                for (final InstructionTargeter targeter : target.getTargeters()) {
                    targeter.updateTarget(target, next);
                }
            }
        }
    }

    Method m = null;

    if (count > 0) {
        System.out.println("Removed " + count + " NOP instructions from method " + mg.getName());
        m = mg.getMethod();
    }

    il.dispose(); // Reuse instruction handles
    return m;
}
 

private InstructionHandle[] getInstructionHandles(final JavaClass clazz, final ConstantPoolGen cp, final Method method) {
    final MethodGen methodGen = new MethodGen(method, clazz.getClassName(), cp);
    final InstructionList instructionList = methodGen.getInstructionList();
    return instructionList.getInstructionHandles();
}
 

private static void test(final File lib) throws IOException {
    final NanoTimer total = new NanoTimer();
    final NanoTimer parseTime = new NanoTimer();
    final NanoTimer cgenTime = new NanoTimer();
    final NanoTimer mgenTime = new NanoTimer();
    final NanoTimer mserTime = new NanoTimer();
    final NanoTimer serTime = new NanoTimer();

    System.out.println("parsing " + lib);

    total.start();
    try (JarFile jar = new JarFile(lib)) {
        final Enumeration<?> en = jar.entries();

        while (en.hasMoreElements()) {
            final JarEntry e = (JarEntry) en.nextElement();
            if (e.getName().endsWith(".class")) {
                byte[] bytes;
                try (InputStream in = jar.getInputStream(e)) {
                    bytes = read(in);
                }

                parseTime.start();
                final JavaClass clazz = new ClassParser(new ByteArrayInputStream(bytes), e.getName()).parse();
                parseTime.stop();

                cgenTime.start();
                final ClassGen cg = new ClassGen(clazz);
                cgenTime.stop();

                final Method[] methods = cg.getMethods();
                for (final Method m : methods) {
                    mgenTime.start();
                    final MethodGen mg = new MethodGen(m, cg.getClassName(), cg.getConstantPool());
                    final InstructionList il = mg.getInstructionList();
                    mgenTime.stop();

                    mserTime.start();
                    if (il != null) {
                        mg.getInstructionList().setPositions();
                        mg.setMaxLocals();
                        mg.setMaxStack();
                    }
                    cg.replaceMethod(m, mg.getMethod());
                    mserTime.stop();
                }

                serTime.start();
                cg.getJavaClass().getBytes();
                serTime.stop();
            }
        }
    }
    total.stop();
    if (REPORT) {
        System.out.println("ClassParser.parse: " + parseTime);
        System.out.println("ClassGen.init: " + cgenTime);
        System.out.println("MethodGen.init: " + mgenTime);
        System.out.println("MethodGen.getMethod: " + mserTime);
        System.out.println("ClassGen.getJavaClass.getBytes: " + serTime);
        System.out.println("Total: " + total);
        System.out.println();
    }
}